Thomas's work and stature as a poet have been much debated by critics and biographers since his death. Critical studies have been clouded by Thomas's personality and mythology, especially his drunken persona and death in New York. When Seamus Heaney gave an Oxford lecture on the poet he opened by addressing the assembly, "Dylan Thomas is now as much a case history as a chapter in the history of poetry", querying how 'Thomas the Poet' is one of his forgotten attributes. David Holbrook, who has written three books about Thomas, stated in his 1962 publication Llareggub Revisited, "the strangest feature of Dylan Thomas's notoriety-not that he is bogus, but that attitudes to poetry attached themselves to him which not only threaten the prestige, effectiveness and accessibility to English poetry, but also destroyed his true voice and, at last, him."
Many critics have argued that Thomas's work is too narrow and that he suffers from verbal extravagance. Those that have championed his work have found the criticism baffling. Robert Lowell wrote in 1947, "Nothing could be more wrongheaded, than the English disputes about Dylan Thomas's greatness ... He is a dazzling obscure writer who can be enjoyed without understanding." Kenneth Rexroth said, on reading Eighteen Poems, "The reeling excitement of a poetry-intoxicated schoolboy smote the Philistine as hard a blow with one small book as Swinburne had with Poems and Ballads." Philip Larkin in a letter to Kingsley Amis in 1948, wrote that "no one can 'stick words into us like pins'... like he [Thomas] can", but followed that by stating that he "doesn't use his words to any advantage". Amis was far harsher, finding little of merit in his work. In 1956, the publication of the anthology New Lines featuring works by the British collective The Movement, which included Amis and Larkin amongst its number, set out a vision of modern poetry that was damning towards the poets of the 1940s. Thomas's work in particular was criticised. David Lodge, writing about The Movement in 1981 stated "Dylan Thomas was made to stand for everything they detest, verbal obscurity, metaphysical pretentiousness, and romantic rhapsodizing".
Despite criticism by sections of academia, Thomas's work has been embraced by readers more so than many of his contemporaries, and is one of the few modern poets whose name is recognised by the general public. Several of his poems have passed into the cultural mainstream, and his work has been used by authors, musicians and film and television writers. The BBC Radio programme, Desert Island Discs, in which guests usually choose their favourite songs, has heard 50 participants select a Dylan Thomas recording. John Goodby states that this popularity with the reading public allows Thomas's work to be classed as vulgar and common. He also cites that despite a brief period during the 1960s when Thomas was considered a cultural icon, that the poet has been marginalized in critical circles due to his exuberance, in both life and work, and his refusal to know his place. Goodby believes that Thomas has been mainly snubbed since the 1970s and has become "... an embarrassment to twentieth-century poetry criticism" his work failing to fit standard narratives and is thus ignored rather than studied.